﻿using System;
using System.Collections.Generic;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;

public partial class example : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {
        if (IsPostBack && Username.Text != "")
            Username.DisplayValidationError("<b>Username Already Taken</b><br/>Please choose a different username.");
    }
}
